Method of making sand drains in situ



Sheet INVENTOR. LEE A. TURZILLO ATTQRNEY Feb. 11, 1969 A. TuRzlLLOMETHOD OF MKING SAND DRAINS IN SITU Filed Mamme, 1965 Feb. 11, 1969 L A.TuRziLLo METHOD OF MAKING SAND DRAINS IN SITU Sheet Filed March 19, 1965INVENTOR. LEE A. TURZILLO ATTORNEY United States Patent O 6 Claims Int.Cl. E021 11 /00; E02d 5 /34 ABSTRACT OF THE DISCLOSURE Method andrrneans for providing in an earth situs a pile or other structuralcolumn different from that of the situs, includes screwing hollowshaftedauger into situs to form bore, and smaller auger is selectively axiallyshifted in the hollow shaft to move closure carried by smaller auger toselectively adjusted spacing of closure from closed position againstinner end of hollow shaft. Larger auger progressively -Withdrawn frombore while rotating smaller auger in hollow shaft, forcibly to conveybore filling material through hollow shaft, past closure and bedispersed and compacted within the bore. Other means provided,separately supplying fluid material to bore through shaft of smallerauger for `combination with materials conveyed into bore by augerilighting.

This invention relates to a method and apparatus for making sand drains,concrete piles, and other columnar structures in an earth situs.

Heretofore, sand drains have been made for the purpose of accomplishingmore effective Water drainage in porous soils in the earths surface.Generally, a deep bore was drilled or cored in the earth and a metalcasing Was forced vertically into the same and lled with sand, and thenthe casing was removed to leave a core of Iwaterpervious sand in thebore. Such sand drains were not always satisfactory, however, because ofa tendency for the sand to bridge between opposite wall portions of thecasing to leave voids or pockets which tended to prevent uniformdistribution and packing of the sand as necessary for attainingeffective drainage. The process of installing and removing the casing,however, tended to score and smear the surface portions of the bore, andreduced the effective permeability of the same. In other words, it wasfound that sand could not be satisfactorily fed into the bored holesthrough pipes or tubes because of a strong tendency for the sand tobridge across the inside of the passages thereof and, thereby, clog thevsame.

One object of the present invention is to provide an -improved methodand apparatus for forming sand drains in the earth, by which theresultant sand drainage core will be uniformly packed and free of voids.

Another object of the invention is to provide an improved method andapparatus for making sand drains, concrete piles, and other columnarstructures to the full depth of drilled -holes in the earth,progressively and simultaneously with removal of the earth materialsfrom the hole 'with the drill.

Still another object of the invention is to provide an improved methodfor making `an effective and eiiicient sand drain, and other columnarstructures, in the earth, to completion, with approximately the sameamount of equipment handling as for augering the hole for the 3,426,538Patented Feb. 11, 1969 columnar structure, and in substantially the samelength of time as nonmally required to auger said hole.

These and other objects of the invention will be manifest from thefollowing brief description and the accompanying drawings.

Of the accompanying drawings:

FIGURE l is a vertical cross-section through a sand drain in the earth,made by use of the improved method and apparatus of the invention.

FIGURE 2 is a vertical cross-section, on the same scale and partlybroken away and in section, illustrating the improved said drain makingequipment, at a point in the method Where the sand drain hole has beenbored to full depth.

FIGURE 3 is an enlarged vertical cross-section, corresponding to thelower portion of FIGURE 2, but illustrating the beginning of theoperation of uniformly distributing sand within the bored hole.

FIGURE 4 is a view corresponding to FIGURE 3, illustrating anotherinitial but subsequent period in the sand distributing operation of saidequipment.

Referring particularly to FIGURE 2, there is illustrated apparatus 10for practicing the method of the invention for making a sand drain 11 inan earth situs (see FIG- URE 1). Such apparatus may include a sectional,continuous flight, hollow-shaft auger 12 rotatably mounted on a suitablecarriage 13, which is vertically movable, by a hoist cable 14, on guiderails 15 of a drilling rig R. A reversing-type hydraulic motor 16 on thecarriage 13 is selectively operable to rotate the auger 12 about avertical axis thereof, through a connecting 'chain drive 17. Thus, theauger 12 is vertically operable to drill a bore 18 of any predetermineddepth.

For feeding Water-pervious material, such as sand 19, into the bore, thehollow shaft 20 may have a smaller hollow-shafted auger 21 independentlyrotatably mounted thereon, as shown in FIGURES 2, 3, and 4. The drivingbit 22, which normally would be aflixed to the lower end of the largerauger, is in this case non-rotatably aixed to the lower end of thesmaller auger, and is provided with a peripheral seat portion 23normally held in abutment with the lower end of the auger shaft 20, toprevent passage of materials into or out of the shaft passage 24. Thesmaller auger 21, however, is selectively vertically reciprocable,between extended and retracted condition with respect to said lower endof auger shaft 20, to open and close the lower end of passage 24, as bymeans of simultaneously operable hydraulic cylinders 25, 25 mounted onthe carriage 13, and selectively operable to reciprocate a support 26for a hydraulic motor 27 which rotatably carries the smaller auger 21.Motors 16 and 27 may be synchronized to rotate as one in clock- Wisedirection, during the operation of auger 12 for drilling the bore 1S.When the bore has been drilled to requisite depth, however, as shown inFIGURE 2, joint rotation of the two augers 12 and 21 is stopped, 4andthe hydraulic lcylinders 25, 25 are operated to ram the smaller auger 21downwardly with respect to the larger auger 12 and, thereby, to open thelower end of shaft passage 24, as shown in FIGURE 3. While the largerauger 12 is slowly raised out of the formed earth bore 18, by means ofhoist cable 14, the hydraulic motor 27 is operated to rotate the smallerauger in counter-clockwise direction, uniformly and continuously to feedsand or other porous 3 material from hopper 28, affixed on carriage 13(see FIGURE 2), downwardly in the auger shaft passage 24, and outthrough the open lower end of the same, with resultant uniform spreadingand packing of the sand from Wall to wall in the bore 18 (see FIGURES 3and 4).

For the purposes described, the rotating bit 22 may be fish-tail shapedto have curvate portions 29, 29 which dig into the soil during thebore-drilling operation. In the reverse rotational operation of the bit,however, said curvate portions conversely will tend to pack the sanddownwardly whereby upon complete removal of the combination auger fromthe bore, the resultant sand drain 11 will be free of objectionablematerials and voids and have uniform water permeability (see FIGURE 1).

Accordingly, the steps of the improved method basically include drillinga bore 18 in the earth formation E, requiring soil consolidation forsupporting a heavy building or other construction thereon, as by meansof the hollow, continuous iiight, hollow-shaft auger 12, topredetermined depth; and while progressively withdrawing the auger toremove the augered earth from the formed bore 18, simultaneously andprogressively force feeding sand through the passage in the auger 12 tolill the space within said bore left by progressive removal of auger 12and the removed earth. As clearly described above, continuous downwardfeeding of the sand 19 may be accomplished by means of the selectivelyoperable small auger 21 relatively rotatable Within the larger augershaft passage 24 to force the sand through said passage and into theangered bore. The continuous mechanical impacting of the sand 19 intothe angered bore, assures uniform distribution and packing of the sandto the full depth of the bore for most effective and eilicientconsolidation of the surrounding earth formations, in accordance withthe stated objects of the invention.

It will be readily apparent that the method and apparatus may have usesfor other than constructing sand drains. That is, loose materials otherthan sand may be mechanically fed through the hollow shaft auger 12 andlikewise progressively compacted to the full depth of the angered bore.As an example, concrete or other tluid cementitious material may be fedinto the bore 18 in this manner to form a solid supporting pile orcolumn, and thereby eliminate the heavy expensive grout-pumpingequipment generally required for installing concrete piling.

If it is desired to fill the bore 18 with material under pressure, suchas self-hardening fluid grout, the same may be pumped from a suitablesource through a swivel joint 31 connected at or near the -upper end ofa conduit extension 32 of small auger 21, the passage 33 in the hollowshaft of auger 21, and outlet ports 34, 34 in driving bit 22, and intothe bore. Fluid grout, for example, may be pumped in this manner whilethe end of the larger auger 12 is open at the bottom, as shown inFIGURES 3 and 4, or closed, as shown in FIGURE 1. Water may be pumpedthrough the shaft of small auger 21 while simultaneously feeding Ia bulkmaterial, such as a concrete mix, down the hollow shaft of said largerauger, and these separately introduced materials may be blended togetheras the auger 12 is withdrawn from the bore, in the manner previouslydescribed,

It is also possible by means of the small a-uger 21, for example, tofeed granular material, such as pea gravel or coarse aggregate fromhopper 28 into the hole 18 (as shown in FIGURES 3 and 4), simultaneouslywith feeding or pumping fluid grout under pressure through the passage33 of the small auger, as necessary, to provide a requisite concrete mixin the hole. Accordingly, the materials may be blended to suit varyingconditions at different levels within the hole, as an example. In thisway, it is possible to form a concrete pile according to Variablespecifications, simultaneously with removal of the earth materials fromthe hole with the hole drilling unit.

When fluid grout is supplied to the bottom of the hole 18 through thepassage 33 of the small auger, with or without additional granularmaterial, as described above, any water and/or residual earth materialleft in the hole 18 will be displaced by the pressurized grout as theauger unit is progressively withdrawn from the hole.

By reference to FIGURE 2, it will be seen that the aforementioned sand,concrete, pea gravel, coarse aggregate, or blends of materials, can besupplied to the relatively iixed hopper 28 through the open top thereofwhile the augers 12 or 21 are rotating or stationary. By the same token,materials conveyed upwardly into the hopper by the smaller auger 21 canbe viewed or sampled for inspection purposes while the two augers arerotating or stationary.

Other modifications of the invention may be resorted to withoutdeparting from the spirit thereof or the scope of the appended claims.

What is claimed is:

1. A method of providing in an earth situs a column of structuralformation diiferent from that of the situs, comprising the steps of:screwing a hollow shafted auger inwardly into the situs to form a boretherein of predetermined depth; selectively axially shifting to variableextent a smaller, continuous Hight auger inwardly within the hollowshaft of the larger auger to carry a closure on the inner end of thesmaller auger to selectively adjusted spacing of the closure inwardlyfrom a closed position against the inner end of the hollow shaft of thelarger auger; and progressively withdrawing the larger auger whilerotating said smaller auger within the hollow shaft to convey borefilling material, from a supply thereof at the upper end of the largerauger, through the hollow shaft to be dispersed past the closureprogressively to lill the bore.

2. A method as in claim 1, wherein said supply of filler material is fedfrom a relatively xed hopper commumeating with said hollow shaft of thelarger auger, and the smaller auger is reversely rotatable forselectively conveying material up the flighting thereof to therelatively fixed hopper.

3. A method as in claim 2, wherein a second filler material from asource of supply is simultaneously fed downwardly through a passage inthe smaller auger to an outlet disposed within the bore below the largerauger for blending convergence with the bore filling material conveyedthrough said hollow shaft.

4. A method as in claim 1, wherein a second filler material from asource of supply is simultaneously fed downwardly through a passage inthe smaller auger to an outlet disposed within the bore below the largerauger for blending convergence with the bore filling material conveyedthrough said hollow shaft.

5. A method as in claim 1, wherein a second liller material from asource of supply is simultaneously fed downwardly through a passage inthe smaller auger to an outlet disposed within the bore below the largerauger for blending convergence with the bore filling material conveyedthrough said hollow shaft, wherein the separately fed materials includea granular substance and hardenable fluid grout forming `a concrete pilein the bore.

6. A method of providing in a situs of an earth formation, a core of adifferent structural formation, comprising the steps of: screwing ahollow drill into the earth formation to form a bore of predetermineddepth therein; and while progressively withdrawing the drill to removethe cored earth from the bore, simultaneously feeding filler materialdownwardly through the hollow drill, progressively to lill the space inthe bore left below the drill upon said progressive Withdrawal of thedrill; said filler material including different materials separately fedtoward blending convergence in the space below the drill ReferencesCited UNITED STATES PATENTS Bowslaugh 61-11 Powell 61-53.64 Ranney.

Ryser etal 61-53.64 Case et al. 61-35 Durston et al. 61-63 Durston etal. 61--11 6 8/1965 Phares et al. 61-53.64 9/1965 Moor (wl-53.64 1/1966Dufresne 61-53.64 9/1966 Landau 61-11 2/1967 Landau 61-11 X FOREIGNPATENTS 1/ 1961 Switzerland. 9/1963 Canada.

U.S. Cl. XR.

UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No.3,426,538 February ll, 1969 Lee A. Turzillo It is certified that errorappears in the above identified patent and that said Letters Patent arehereby corrected as shown below:

Column 6, line 5, cancel "3,030,656 2/1967 Landau 6l-ll X Signed andsealed this 17th day of November 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M, Fletcher, Jr.

Commissioner of Patents Attesting Officer

